Accident Overview
On June 7, 2024, at about 0930 mountain daylight time, a Beech V35A airplane registered as N150WR was destroyed in an accident near Arvada, Colorado. The pilot reported no injuries, while two passengers sustained serious injuries and a third passenger was fatally injured. The flight was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight History
The pilot intended to fly from Centennial Airport (APA), Englewood, Colorado, to Northern Colorado Regional Airport (FNL), Fort Collins, Colorado, a distance of about 53 nautical miles. A preflight inspection and engine runup revealed no anomalies. The airplane departed at about 0915 according to ADS-B data. The takeoff and climb were uneventful until reaching 7,000 feet, where the pilot noted a slight drop in manifold pressure, though the airplane continued climbing.
At about 0927, the pilot sent a text message to his mechanic at FNL stating he was only getting 20 inches of manifold pressure at full throttle. The pilot then diverted to Rocky Mountain Metro Airport (BJC), Broomfield, Colorado. At about 0928, the pilot contacted the tower controller, reporting that his oil light was on and he was losing oil pressure. The controller instructed a straight-in approach to runway 30R. The pilot subsequently reported losing power quickly and that he might have to land elsewhere. When asked about a safe landing site, the pilot indicated he was trying to find a field or park and had something in sight.
Emergency Landing
The pilot selected a residential street for the forced landing and chose not to extend the landing gear to avoid hitting obstructions. The airplane impacted the pavement hard. The pilot stated a fire immediately started on the left wing and spread quickly to the right wing.
Eyewitness Accounts
Three eyewitnesses near the flight path described an airplane traveling past their residences trailing smoke; one witness noted white smoke. Each described the engine sound differently, but consistently indicated the engine was in distress.
Wreckage and Engine Examination
Examination of the accident site showed the airplane impacted a tree before landing on a street with the landing gear retracted. It struck a parked truck and came to rest in a front yard about 500 feet from the tree. The majority of the airplane was consumed by a postimpact fire.
A postaccident examination of the engine revealed that the oil line adapter fitting to the turbocharger was missing one bolt and the other was loose. Both bolts securing the adapter fitting for the oil return line to the engine on the turbocharger were also loose. No other anomalies were noted beyond the missing and loose bolts. Police photos confirmed one bolt was missing from the top oil line fitting at the accident site before the wreckage was moved.
An engine teardown examination found that the No. 5 connecting rod separated from the crankshaft, exhibiting lubrication distress and smeared bearing material. The other connecting rod journals and main bearing journals showed varying degrees of discoloration consistent with heat and lubrication distress.
Maintenance History
Review of maintenance documentation revealed no logbook entries related to the oil line fittings on the turbocharger during the previous five years. The most recent annual inspection was completed August 1, 2023, at a tachometer time of 6,091.2 hours. Maintenance personnel reported that the pilot had dropped off the airplane for an oil change three days before the accident. The technician who performed the work removed and inspected the oil filter, replaced four bolts, washers, and nuts on the front muffler clamp, and torqued as required. Some of the replaced hardware was in the vicinity of the oil line fittings on the turbocharger, but replacement of exhaust hardware would not have required loosening the oil line fitting bolts. The technician reported no observed fluid leaks during a post-maintenance engine run and leak check. The pilot retrieved the airplane the day before the accident, performed a lengthy preflight, and completed one touch-and-go takeoff and landing before departing to APA, with the airplane performing well during that flight.